Effect of doping and defects on the electronic properties of MoS/WSe bilayer heterostructure: a first-principles study.

This work studies the effect of Nb, Mo, Re dopant, and Se vacancy in WSe on the electronic and optical properties of the MoS/WSe bilayer heterostructure based on first-principles calculations. Our research shows that the MoS/WSe bilayer heterostructure exhibits a type-II band alignment with a valence band offset (VBO) of 1.07 eV and a conduction band offset (CBO) of 1.00 eV. It also shows that different dopants or defects can considerably modulate the energy band alignment and interlayer charge transfer of the heterostructure. Owing to the orbital hybridization of the dopant atoms with other atoms and the consequent enhancement of the coupling between the two structural layers, a transition of the band alignment from type-II to type-I is realized with the Re dopant. The effect of doping and defects on the electronic properties of heterojunctions contributes to applications in high-performance optoelectronic devices.